// cv::putTextZH(), the enhanced version for cv::putText, support drawing

#ifndef CV_PUTTEXTZH_H
#define CV_PUTTEXTZH_H

#include <iostream>

#include "opencv2/opencv.hpp"

//----------------------------------------------------------------------
// declaration
//----------------------------------------------------------------------

namespace cv {
static void putTextZH(cv::Mat& dst, const char* str, cv::Point org, cv::Scalar color, int fontSize, const char* fn = "Arial", bool italic = false, bool underline = false);
}

//----------------------------------------------------------------------
// implementation
//----------------------------------------------------------------------

#define NOMINMAX
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#undef NOMINMAX
#undef WIN32_LEAN_AND_MEAN

static void GetStringSize(HDC hDC, const char* str, int* w, int* h) {
    SIZE size;
    GetTextExtentPoint32A(hDC, str, strlen(str), &size);
    if (w != 0)
        *w = size.cx;
    if (h != 0)
        *h = size.cy;
}

namespace cv {

void putTextZH(cv::Mat& dst, const char* str, cv::Point org, cv::Scalar color, int fontSize, const char* fn, bool italic, bool underline) {
    CV_Assert(dst.data != 0 && (dst.channels() == 1 || dst.channels() == 3));
    int x, y, r, b;
    if (org.x > dst.cols || org.y > dst.rows)
        return;
    x = org.x < 0 ? -org.x : 0;
    y = org.y < 0 ? -org.y : 0;
    LOGFONTA lf;
    lf.lfHeight = -fontSize;
    lf.lfWidth = 0;
    lf.lfEscapement = 0;
    lf.lfOrientation = 0;
    lf.lfWeight = 5;
    lf.lfItalic = italic;        // 斜体
    lf.lfUnderline = underline;  // 下划线
    lf.lfStrikeOut = 0;
    lf.lfCharSet = DEFAULT_CHARSET;
    lf.lfOutPrecision = 0;
    lf.lfClipPrecision = 0;
    lf.lfQuality = PROOF_QUALITY;
    lf.lfPitchAndFamily = 0;
    strcpy_s(lf.lfFaceName, fn);
    HFONT hf = CreateFontIndirectA(&lf);
    HDC hDC = CreateCompatibleDC(0);
    HFONT hOldFont = (HFONT)SelectObject(hDC, hf);
    int strBaseW = 0, strBaseH = 0;
    int singleRow = 0;
    char buf[1 << 12];
    strcpy_s(buf, str);
    char* bufT[1 << 12];  // 这个用于分隔字符串后剩余的字符，可能会超出。
    // 处理多行
    {
        int nnh = 0;
        int cw, ch;
        const char* ln = strtok_s(buf, "\n", bufT);
        while (ln != 0) {
            GetStringSize(hDC, ln, &cw, &ch);
            strBaseW = max(strBaseW, cw);
            strBaseH = max(strBaseH, ch);
            ln = strtok_s(0, "\n", bufT);
            nnh++;
        }
        singleRow = strBaseH;
        strBaseH *= nnh;
    }
    if (org.x + strBaseW < 0 || org.y + strBaseH < 0) {
        SelectObject(hDC, hOldFont);
        DeleteObject(hf);
        DeleteObject(hDC);
        return;
    }
    r = org.x + strBaseW > dst.cols ? dst.cols - org.x - 1 : strBaseW - 1;
    b = org.y + strBaseH > dst.rows ? dst.rows - org.y - 1 : strBaseH - 1;
    org.x = org.x < 0 ? 0 : org.x;
    org.y = org.y < 0 ? 0 : org.y;
    BITMAPINFO bmp = {0};
    BITMAPINFOHEADER& bih = bmp.bmiHeader;
    int strDrawLineStep = strBaseW * 3 % 4 == 0 ? strBaseW * 3 : (strBaseW * 3 + 4 - ((strBaseW * 3) % 4));
    bih.biSize = sizeof(BITMAPINFOHEADER);
    bih.biWidth = strBaseW;
    bih.biHeight = strBaseH;
    bih.biPlanes = 1;
    bih.biBitCount = 24;
    bih.biCompression = BI_RGB;
    bih.biSizeImage = strBaseH * strDrawLineStep;
    bih.biClrUsed = 0;
    bih.biClrImportant = 0;
    void* pDibData = 0;
    HBITMAP hBmp = CreateDIBSection(hDC, &bmp, DIB_RGB_COLORS, &pDibData, 0, 0);
    CV_Assert(pDibData != 0);
    HBITMAP hOldBmp = (HBITMAP)SelectObject(hDC, hBmp);
    // color.val[2], color.val[1], color.val[0]
    SetTextColor(hDC, RGB(255, 255, 255));
    SetBkColor(hDC, 0);
    // SetStretchBltMode(hDC, COLORONCOLOR);
    strcpy_s(buf, str);
    const char* ln = strtok_s(buf, "\n", bufT);
    int outTextY = 0;
    while (ln != 0) {
        TextOutA(hDC, 0, outTextY, ln, strlen(ln));
        outTextY += singleRow;
        ln = strtok_s(0, "\n", bufT);
    }
    uchar* dstData = (uchar*)dst.data;
    int dstStep = dst.step / sizeof(dstData[0]);
    unsigned char* pImg = (unsigned char*)dst.data + org.x * dst.channels() + org.y * dstStep;
    unsigned char* pStr = (unsigned char*)pDibData + x * 3;
    for (int tty = y; tty <= b; ++tty) {
        unsigned char* subImg = pImg + (tty - y) * dstStep;
        unsigned char* subStr = pStr + (strBaseH - tty - 1) * strDrawLineStep;
        for (int ttx = x; ttx <= r; ++ttx) {
            for (int n = 0; n < dst.channels(); ++n) {
                double vtxt = subStr[n] / 255.0;
                int cvv = vtxt * color.val[n] + (1 - vtxt) * subImg[n];
                subImg[n] = cvv > 255 ? 255 : (cvv < 0 ? 0 : cvv);
            }
            subStr += 3;
            subImg += dst.channels();
        }
    }
    SelectObject(hDC, hOldBmp);
    SelectObject(hDC, hOldFont);
    DeleteObject(hf);
    DeleteObject(hBmp);
    DeleteDC(hDC);
}
}  // namespace cv

#endif  // CV_PUTTEXTZH_H
